Viktor S Rashkes

US Patent:

20020079906, Jun 27, 2002

Filed:

Dec 21, 2000

Appl. No.:

09/742606

Inventors:

Viktor Rashkes - Plymouth MN, US
Alexander Golubev - Maple Grove MN, US

International Classification:

H04B003/46
H01H031/02

US Classification:

324/544000

Abstract:

A sensor and associated circuits are provided for on-line monitoring of the state of the high-voltage insulation in electrical equipment with capacitance tap. In this arrangement, both the power frequency signal and the radio frequency signals associated with partial discharge activity are sensed. These signals are transmitted from the sensor to remote monitoring instrumentation via one connecting cable. The sensor contains a surge arrester in parallel with a capacitor shunt, a radio frequency current transformer and a connecting circuit. The polarity terminal of the primary winding of the radio frequency current transformer is connected to the tap output. The non-polarity terminal is connected to the common connection point of the surge arrester and the capacitor shunt while the second terminals of these components are connected to the local ground. The non-polarity terminal of the secondary winding of the radio frequency current transformer is connected to the non-polarity terminal of its primary winding, and the polarity terminal-to the signal conductor of the connecting circuit. The second conductor of the connecting circuit is connected to the local ground. Both the power frequency signal and the radio frequency signal are transmitted on the same cable from the sensor to the remote monitoring instrumentation.